Train control system



1932' F. H. NICHOLSON TRAIN CONTROL SYSTEM Filed Feb. 18, 1932 ill/0% m INVENTOR FRANK H. NICHOLSON QW/IVM 4 ATTORNEY Patented Oct. 11, 1932 rrrn STATES FRANK a nrcnonson, or EDGEWOOD, PENNSYLVANIA, AssIenoR 'ro. THE Union V swrrorr & SIGNAL COMPANY, or swIssvAnE, rnnnsynvanrn; a conronnrron' or PENNSYLVANIA TRAIN :conrnor. SYSTEM Application filed February 18, 1932 Serial No. 593,726. I

This invention relates to train control systems, particularly of the intermittently controlled type.

In the accompanying'drawing the invenl tion is disclosed in a preferred and concrete,

though somewhat diagrammatic, form.

In systems of the character here contemplated, it is customary to provide a control relay on the train which is normally held energized by current from a source of power connected to said relay through a stick con tact 1n the form of a polarized armature. Wayside control means in theform of inductors located at different control points along .15 the line of way are utilized, under adverse traffic conditions, to reversethe position of the polarized armature thereby rupturing the circuit through, and deenergizing the relay, and whereby also a circuit through a brakeat, setting device such as a magnet valve is ruptured so that the brakes are applied. Means have also heretofore been used whereby it the engineer is on the alert he may'forestall the automatic brake application and retain "-28 the control relay energized by a manually operated acknowledgment device to be actuated by the engineer within a predetermined time before passing an adverse control point. In the arrangement just outlined, the engi- 3'0 neer can run the train at an uninterrupted speed as long as he is on the alert andacknowledges the adverse trafiic conditions.

The main object and feature ofthis invention is to compel a slowing down of the train out, however, imposing a continuing speed limitation on the train after an adverse control point such as a caution signal is passed. Although, as stated, no continuing speed limitation is imposed, yet this arrangement renders it unlikely that the engineer will overrun a stop signal after passing a caution signal. I

In the eX-emplification shown in the draw- 4 ing, a control relay is arranged on the train,

which relay is normally held energized by a circuit leading from a suitable source of power connected to B and from thence over wire 1 to polarized armature 2, wire 3, coil of re- Qt lay S, wire 4, secondary 5 of engine receiver when passing an adverse control point with- 6,'wire 7, part of primary 8, wire 9, magnet valve or brake-setting device H and common return C, back to source. This is a high resistance circuit so that the magnetizingeffe'ct on engine receiver 6 is negligible. Another circuit which is normally closed is from source to B wire 1, armature 2, wirelO, all of primary 8 of receiver 6, wire 9, coil-of-H and common return C back to source. This is a low resistance circuit andmagnetizesthe receiver. As long as magnet valve H remains energized, the brakes are heldofi. Arranged along the line of way at difierent control points are inductors 12, which under clear traflic conditions exercise no eflective control on the engine receiver, but which under adverse traific conditionsactto reduce, or under certain conditions, to reverse the current through relay S and'thus cause armature 2 to release thereby. opening the contacts of said relay S so that it, aswell as magnet valve H, becomes deenergized. In these circumstances an automatic brake application is initiated. 14 indicates a speed-governed device connected to an axle or otherwise controlledby the speed of thetrain, and this device controls here two contacts 15 and 16 such that when the train is running below a given speed said contacts are in their closed pos'i- 'tion, but when the train is running above a contacts closed, a circuit can be traced from,

13, wire 1, contact 15, wire' 22, contact 18, wire 23-, wire '3, coil of S, wire 4:, secondary 5, part of primary 8, wire 9, magnet valve H, and commonreturn Cy'and that 'another circuit can betraced from B wire 1, contact 15, wire 22,,contact 17 ,wire 24, wire 10,

9, magnet valve H and common return C. It will be noted that these circuits are not dependent for their continuity upon the position of armature 2, and that therefore both relay S and magnet valve primary 8, wire v H can-be energized regardless of the position of armature 2. It is equally clear that unless the train is running below a given speed contact 15 will not be closed, and it is also clear that unless the effect of spring or weight 21 is counteracted, contacts 17 and 18 will not be closed. Manually operated means to ex- 26 by means of pipes 27 and 28, while at the If the train is running same time pressure 1s cut off from acknowledgment relay 20, (below diaphragm 19). When, however, the acknowledgment valve is turned, communication iscut off between pipes 27 and 28,- while at the same time communication is established between pipes 28 and 29 which latter leads to relay 20. It will-now be seen that when the engineer receivesan indication, as by means of awayside signal, that the train is approaching an adverse control point, he may then, if he is on the alert, operate valve thereby causing fluid pressure topa-ss beneath diaphragm 19 so as to close contacts 17 and 18. below a given speed,

- a contact 15 will likewise be closed and relay -plication S willlremain energized'and consequently an automatic brake application will be prevented when passingthe adverse control point.

After an adverse control point has been passed "at reduced speed,-the engineer is free to accelerate the speed of the train because no continuing speed limitation is imposed'by the systemunder theseconditions.

- If, however, the train is not running at reduced speed when passing an adverse control point, the'engineman must suppress the automatic brake application by making a brake pipe reduction of a predetermined amount, which prevents the automatic apk by the functioning of' the well- 1known suppression feature. The

been brought below the low speed limit, at whichtime governor contacts 15 and 16 will close, and an acknowledgment can be effected. As soon as the acknowledgment has been effected the brakes can'be released in the usual manner, and the train speed will then be somewhat below the prescribed low speed limit.

I In accordance withwell-known practice in air-brake equipment and forestalling devices,

oncean automaticbrake application is inby first placing brakes 7 must be held applied until the speed has 5 itiatedit will continue. To release the pres ent system after an automatic brake application has occurred, it is necessary to brlng the speed of the train below the predetermined limit and also to operate the acknowledgment valve thereby energizing relay S and magnet valve H,'after which a recharge of the. brake pipe can be initiated as usual the brake valve handle in the lap'position to restore the brake application valve to its normal'position and then moving the brake 'valve handle to either running or release position; Also, the acknowledgment valve should be returned to the position where the acknowledgment reservoir is replenished. V

It is unnecessary to describe the action'of the system when passing a non-adverse control point because inductor 12 will, in these circumstances, have no controlling effect upon the system. It remains, however, to be said that contact 16 leads to a conductor 31 that extends to common'return C, in which conductor 31 is a lamp 32 that is lighted when the train is running below agiven speed, but which becomes extinguished when the speed of the trainrises above a given point. 33 is a spark arrester located in conductor. 34 that extends betweenwire 10, leading to armature 2, and common return C. It is unnecessary to go into the purpose of this spark arrester here.

I claim:

1. A train-carried control system including; a normally energized control relay; a normally energized brake-setting device; two circuits controlled by afront contact of the control relay, one circuit including said control relay and brake-setting device in' series, and theother circuit including the brake-setting device; and manually controlled means to maintain said circuits closed independently of the'front contact of the con trol relay provided the train is running below a given speed. I

2. A train-carried control system including: a normally energized control relay; a

normally energized brake-setting device; a

receiver having a primary and a secondary winding; two circuits controlled by a front contact of the control relay, one circuit' includin g in series the control relay, the secondary winding and part of the primary winding of the receiver and the brake-setting device, and the other circuit including in series all of the primary winding of the receiver and the brake-settingdevice; and manually controlled means to maintain said circuits closed independently of the front contact of the control relay providedthe train is running below 'a given speed. i

In testlmony whereof I afliX my signature.

FRANK H. NICHOLSON. 

